The award-winning, patent pending Adjustable Phaser Locks for the 5.0L Coyote Modular V8 Engines allow fully adjustable locking over the OEM phaser range (50 degrees) by using a stock timing set, phaser system, bolts with special plugs and slotted degree plates. The locks are easy to adjust on the engine and include a 4 crank degree (2 cam degrees) mark on the outer diameter for accurate adjustment. They allow aftermarket race cams to be physically degreed and locked to ensure adequate piston to valve clearance and precise centerline control at very high RPM under extreme conditions, independent of any computer or mapping. Locking is required with the FAST™ XFI™, XFI 2.0™ and other aftermarket EFI systems.